Terminal device



June 8, 1965 A Y P. K. TURNER TERMINAL DEVICE Filed July 2, 1962 UnitedStates Patent 0 pas 3,188,597 'IERMlNAL DEVICE Prescott K. Turner,Fairfield, Conn., assigner to General Electric Company, a corporation ofNew Yer-lr Filed .lniy 2, 1952, Ser. No. 2%,943 1 Claim. (Cl. 339-14)The present invention relates to electrical terminal devices, and isparticularly applicable to the type of electrical terminal devices whichhave flexible ground-ing leads extending outwardly therefrom.

Terminal devices having flexible grounding leads have seen widespreaduse in cordsets for various appliance applications, such as, forexample, in electric washing machines, air conditioners and dishwashers.For these applications, it is important that such devices be readilyinstallable, and also of safe and reliable construction. PriorV artdevices of the variety referred to have been found, in general, to berelative.y expensive to manufacture. Accordingly, an important object ofthe present invention is to provide an improved cord terminal devicewhich includes a flexible grounding lead and is readily and economicallymanufacturable.

An additional object of this invention is .to provide an improvedterminal device for a cord wherein a flexible grounding lead is arrangedin such a manner that it prohibits the possibility of short circuiting.

A further object of my invention is to provide an improved cord terminaldevice which may be readily mounted in a supporting panel to provide aneffective strain relief and a terminal block for the ends of associatedconductors.

ln carrying out my invention, in one form thereof, I have provided aterminal device which is attached to one end of an electric oord. Theconductors of .this cord are of substantially the same length and theyenter into a molded insulating body from one end wall thereof. A pair ofspaced apart contact prongs extend outwardly from another end wall ofthe body and are connected to the bared ends of a pair of associatedconductors of the cord within the body. In this arrangement, to providean improved means for grounding the device, a third conductor of thecord is looped over within the insulating body so that a flexibleportion thereof extends outwardly from the wall of the body throughwhich the conductors enter. The bared end of this flexible portion hasan annular grounding contact connected thereto. The iiexible portion ofthe third conductor and the grounding contact are of such a length thatthe grounding contact is unable to engage the Contact prongs, therebyprohibiting the possibility of the grounding contact short circuitingwith the contact prongs. In addition, since conductors of substantiallythe same length are utilized, there is no Waste in cordage involved inpreparing the conductors for attachment to the insulating body of theconnector. Y

Further aspects of my invention will become apparent hereinafter, andthe specification concludes with a claim particularly pointing out anddistinctly claiming the subject matter which I regard as my invention.The invention, however, as to organization and method of utilization,together with further objects and advantages thereof, may best beunderstood by reference to the following description when taken inconjunction with the accompanying drawing, in which:

FIG. l is a side elevation view partially in full and partially insection, of an improved terminal device embodying [one form of thepresent invention, the device being mounted in a suitable supportingpanel;

FIG..2 is a front view of the improved terminal device j posed groundingconductor Ztl therebetween.

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FIG. 4 is a perspective view of the device of FIG. 1;

FIG. 5 is a sectional view taken generally along the lines 5-5 of FIG.l, with the screw removed;

FIG. 6 is a side elevation view partially in full and partially insection, of an improved panel mounted terminal device embodying myinvention, in alternate form thereof; and

FIG. 7 is a front View of the device of FIG. 6.

Referring iirst to'FIGS. 1-4 of the drawing, there is illustrated anelectric power cord it), and a terminal device or cord connector l2(FIG. 2) having a pair of contact prongs or blades le for makingengagement with the female contacts of a suitable appliance (not shown).The device l?, and the illustrated portion of power cord lll are locatedat one end of a cordset, the other end thereof including a plug forengagement with a suitable power outlet. The terminal device 12 issecurely positioned on the panel lo of an appliance, and furnishes powerto the appliance for operation thereof through power cord lil.

Considering now more particularly the structure of terminal device l2and cord'lt, attention is initially directed to FIGS. 4 and 5. Cord 1liis a relatively flat or oval shaped three-conductor rip cord, andincludes two outermost insulated circuit conductors i8 with a centrallydis- .The conductors' i8 and .Ztl are normally disposed in parallelrelationship t-o each other. Each of the conductors 18 and 20 includes anumber of stranded wires (as shown in FIG. 5) which are insulated by theextrusion of a suitable thermoplastic insulating jacket 22 thereover,such as polyvinyl chioride. A very thin coating 24 of thermoplasticmaterial covers conductor 2d within jacket 22, its function being tolprovide a relatively permanent identification means which will not tendto fray or wear off when the center conductor Ztl is exposed after theseparation of the two outermost circuit conductors 13. It is arequirement of the National Electrical Code that the groundingconductor, such as the one disclosed herein shall be readily identiableby a green color, and covering 24 is therefore so colored.

For effectively supporting and insulating the connections betweenconductors It and their associated contact blades a4 and providing asimplified strain relief therefor, as shown in FIGS. 1, 4, and 5, anangularly shaped insulating body 32 has been provided. Moreparticularly, the body 32 has an angularly shapedV profile ((*FIG 1),and from upper end 3i? to lower end 34, it includes section 36, throughwhich the contact prongs i4 extendV outwardly, and section 395 fromwhich the grounding conductor 2li extends outwardly. The arrangement ofgrounding conductor Ztl in the insulating body 32 helps to prohibit thepossibility of short circuiting and also helps to reduce the cost ofmanufacturing the terminal device, as shall become apparent hereinafter.

To secure the device l2 to panel 16 in a simple and expeditious manner,an aperture dil is formed through section 38 of the insulating body 32.(See FIG. 1.) A screw 42 is extended through the aperture 40 from theright side thereof, viewing FIG. 1, and the outer end of the screw isthreaded into engagement with a tapped opening 44 of panel 16 to fastenthe connector insulating body 32 thereto. In the illustrated embodiment,a washer 46 is placed on screw 42 between its hexagonal head and theadjacent surface of section 38. To prevent rotation of the device l2with respect to the panel 16, as shown in FIG. 1, the contact bladesection 36 of body 32 is extended through an aperture 48. In theillustrated embodiment of FIG. 1, aperture 48 is formed in a transverse`wall Vdisposed in angular relationship to spaced apart parallel walls16a and lob of the panel 16.

Turning now to a detailed explanation of an important amasar aspect ofthe present invention, attention is directed to FIGS. 4 and 5. Inaccordance with the present invention, the contact blades 14 extendoutwardly from end 30 of insulating body 32. Grounding conductor 2Gextends outwardly from the opposite end 34 of body 32 and is arranged inrelationship thereto to prohibit the possibility of short circuiting thegrounding conductor to the blades 14. In manufacturing the terminaldevice 12, the conductors 18 and Ztl are all cut to substantially thesame length. Thus, if grounding conductor 2t) were disposed alongside ofconductors 1S, within body 32, and the free end of conductor 20thereupon extended in the same direction as the free ends of conductors1S, the position which conductor 20 might then assume is shown by thephantom lines in FIG. 5. By utilizing conductors which are all ofsubstantially the same length, the length of grounding conductor whichis required for each terminal device 12 is the same as the length ofpower conductor required, thereby obviating the burdensome cost of scrapwhich has been inherent in many of the prior art devices wherein thegrounding conductor has a greater length than the circuit conductors.The terminal device 12 of the present invention, may thus bemanufactured at an economical cost.

As shown in FIGS. l and 4, the grounding conductor 20 enters the lowerwall 34 of insulating body 32 in parallel side-by-side relationship withcircuit conductors 1S. The bared ends of the outermost circuitconductors 1S are crimped to the inner ends of blades 14 (FIG. 5) anddisposed within body 32 near upper end S) thereof. However, groundingconductor 2@ is looped over and doubled back toward itself at (FIG. l)within the body 32 near bottom end 34 and arranged so that it extendsoutwardly from end 34 in a direction opposite to the direction in whichthe contact prongs 14 face. The doubled back portion 50 of the conductor2t) is encapsulated by the molded insulating body 32. A ring-shapedcontact 54 is crimped to the bared free end of grounding conductor 2?.The combined length of exposed flexible grounding conductor 20 andcontact 54 is such that contact 54 cannot reach either of the contactprongs 1.4 at the other end of the insulating body. In View of thelength, and looped arrangement of grounding lead 20 and the positioningthereof in device 12., the possibility of short circuiting between thegrounding conductor 2G and the circuitV conductors 18 is prohibited. Itwill thus be seen that the improved terminal device 12 is of extremelysafe and reliable construction.

To connect/the grounding Contact 54 of the device 12 to lpanel 16, asshown in FIG. l, screw 56 is extended through the aperture of theringshaped contact54 and engages tapped hole 5S of the panel 16. Topreclude the possibility of short circuiting between the outermost endsof the contact prings 14, an elongated tongue-like insulating barrier 60extends outwardly from end 3d of body 32. Barrier 60 is disposed betweenand generally parallel to the spaced apart contact prongs 14.

FIGS. 6 and 7 represent a modified form of my invention wherein terminaldevice 112 has been employed. For device 112, the same referencenumerals have been employed to indicate connector parts and associatedconductors which have heretofore been described for device 12. Parts ofdevice 112 which have a modified structure in comparison to thestructure of their correlative parts for device 12, but perform the samebasic functions are identified by the same two reference numerals withthe numeral 1 prefixed thereto.

The basic difference between terminal device 112 and device 12 residesin the fact that device 112 has Vits contact gong-s 14 facing angularlyoutwardly, or to the right of flat panel 116 (viewing FIG. 6), whereasthe device 12 is constructed so that its contact prongs-14 faceangularly inwardly or to the left of the panel 16 (viewing FIG. 1), andextend through the panel 16. The insulating body 132 of device 112. thusincludes section 136 through which the contact prongs 14 extendangularly outwardly, and section 13S which is disposed in angularrelationship to section 136. The grounding conductor 29 extendsdownwardly from end 134 of the insulating body 132 in the same manner aspreviously described for device 12 and is also fastened to the panel 116in the same manner. Device 112 is fastened to the flat panel 116 by theextension of screw 42 through aperture 40 of the insulating body, theouter end of the screw 42 being in threaded engagement with the tappedhole 44 of the panel 116.

To prevent rotation of terminal device 112 in panel 116, a rectangularboss 161 is formed on the side of section 13S of the insulating body 132which faces the panel 116. Boss 161 enters a suitable rectangularaperture 148 formed in the panel 116 and cooperates therewith topreclude any rotation of device 112 with respect to the panel after itis fastened thereto by means of screw 42.

In assembling the improved terminal devices of the present invention,the cord 10 with the two circuit conductors 18 and grounding conductor20 is initially cut so that each conductor is separate for a distanceand is of substantially the same length. The contact prongs 14 arethereupon crimped to the bared ends and adjacent insulation ofconductors 18, and the grounding contact 54 is crimped to the bared endof grounding conductor 20. The conductors 13 and 20 are then positionedin the mold with the grounding conductor 20 looped over, as shown inFIG. 5, so that the free end of conductor 20 and its associated contact54 faces in a direction generally opposite to thedircction of the freeends of the two circuit conductors 18 and their associated contactblades 14. The insulating body is then molded around the connectionsbetween circuit conductors 1S and prongs 14 in the manner illustrated inFIG. 5, with the grounding conductor 20 extending outwardly from thebottom end of the insulating body through which the conductors of cord10 initially enter.

It will now therefore be seen that my new and improved cord terminaldevice as illustrated herein provides for the novel arrangement of aexible grounding lead and reduces the cost of manufacture of the devicewhile also prohibiting the possibility of short circuiting between thegrounding contact and the main circuit contacts. It will further beunderstood that the terminal device of the present invention maybereadily mounted in a supporting panel to provide a strain relief and aterminal block for the ends of associated conductors.

While in accordance with the patent statutes, I have de scribed what at-present are considered to be the preferred embodiments of my invention,it will be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from my invention,and I, therefore, aim in the following claim to cover all suchequivalent variations as fall within the true spirit and scope of thisinvention.

What I ciairn as new and desire to secure by Letters Patent of theUnited States is:

For use with a panel, a cordset comprising a cord and an electricalterminal device adapted to be supported by the panel, said deviceincluding a molded insulating body attached to one end of a cord, saidcord including at least three conductors of substantially the samelength and entering into said insulating body from a rst end wallthereof, a pair of spaced apart power contacts facing outwardly from asecond end wall of said body, said power contacts being connectedrespectively to the bared ends of two associated power conductors ofsaid cord within said body, the other of said three conductors of saidcord being doubled back upon itself within said body and including anexternal portion extending outwardly from said first end wall of saidinsulating body, said doubled back portion of said other conductorencapsulated by said insulating body and held in fixed relation to saidtwo associated power conductors and contacts by said insulating body, agrounding contact connected to the free 5 6 end of the external portionof said other conductor, said 1,881,883 10/ 32 Noble 339-125 externalportion and grounding contact being of such a 2,207,477 7/40 Blackmon339-66 length that the grounding contact is unable to engage said2,654,077 9/53 McLoad 339-148 X power contacts, thereby prohibiting thepossibility of said 2,723,330 11/55 Howard 339....10 grounding contactshort circuiting with said power con- 5 2,869,091 1/59 Robards 339 192tacts, and fasteningmeans for securing said terminal de- 2,986,718 5 /61Bender 339 14 vice to the panel.

References Cited bythe Examiner FOREIGN PATENTS 434,142 9/ 26 Germany.

UNITED STATES PATENTS 10 207,092 11/23 Great Britain.

286,963 10/83 Reed 339--148 1,157,026 10/15 Meschenmoser. JOSEPH D.SEERS, Primary Examiner.

